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LocalJSON

Offline JSON Mapper, Formatter & CSV Converter
100% Client-Side Secure

1. Input Dataset

JSON Array

2. Schema Pipeline

3. Interactive Grid

No live dataset loaded yet. Paste your array on the left.

How It Works

LocalJSON runs entirely in your browser — no uploads, no servers, no tracking. Here's the workflow:

1

Paste Your JSON

Paste a JSON array into the input area. LocalJSON auto-detects the structure and shows all available columns.

2

Map & Select Columns

Choose which fields to keep, rename columns for clarity, and reorder them. Perfect for cleaning messy API responses.

3

Preview Live Grid

See your mapped data in an interactive table. Sort, scroll, and verify before exporting.

4

Export CSV

Download as UTF-8 CSV with BOM — ready for Excel, Google Sheets, or your data pipeline.

Use Cases

Built for developers, analysts, and B2B teams who work with JSON daily.

API Response Debugging

Paste raw API responses, filter to relevant fields, and export clean CSV for testing or documentation.

B2B Data Cleaning

Map inconsistent vendor data to your schema. Rename columns, drop nulls, standardize formats — all client-side.

JSON to CSV for Excel

Convert nested JSON arrays to flat CSV with UTF-8 BOM for perfect Excel compatibility. No online converters needed.

Offline & Air-Gapped Work

Pro Offline Version runs without internet. Ideal for secure environments, compliance workflows, and travel.

Frequently Asked Questions

Quick answers to common questions about LocalJSON.

Is my JSON data sent to a server?
No. LocalJSON runs 100% in your browser. Your data never leaves your device — no uploads, no tracking, no server processing.
Does LocalJSON work offline?
Yes. Once loaded, LocalJSON works completely offline. The Pro Offline Version is a standalone HTML file that requires no internet connection at all.
What is the free tier limit?
Free tier allows 3 actions per day (format, map, or export = 1 action each). Counter resets at midnight local time.
How do I upgrade to Pro?
Purchase a license key (format: LJSON-PRO-XXXXXXXX) from our store, then enter it in the app. Pro unlocks unlimited actions permanently.
Can I convert JSON to CSV?
Yes. Map your JSON array columns, then export to CSV (UTF-8 with BOM) for Excel compatibility.
What browsers are supported?
Any modern browser with ES2020 support: Chrome 80+, Firefox 75+, Safari 14+, Edge 80+.

Free vs Pro Comparison

Choose the plan that fits your workflow.

Feature Free Pro
Daily Actions 3 / day Unlimited
JSON Formatting ✓ ✓
Column Mapping & Renaming ✓ ✓
CSV Export (UTF-8 BOM) ✓ ✓
Offline Version (Standalone HTML) ✗ ✓
Inline Column Renaming ✗ ✓
One-Click Deduplication ✗ ✓
License Type Free Forever Lifetime ($5)